热轧Φ6 ~40 mm HRB500E螺纹钢筋的生产实践

根据GB/T 1499.2-2018标准,水钢设计了Φ36～40 mm HRB500E螺纹钢筋的内控成分为（%）0.22～0.25C、0.60～0.70Si、1. 50～1.60Mn、0.11～0.13V、P≤0. 045、S≤0. 045。采用"100 t顶底复吹转炉冶炼-挡渣出钢-脱氧合金化-LF炉精炼-160方坯连铸-方坯加热-棒材轧制-空冷"的工艺流程,生产出的Φ36 mm HRB500E螺纹钢筋的屈服强度Re_L⁰ 540～580 MPa,抗拉强度R_m⁰ 705～735 MPa,断后伸长率A 15. 5%～20. 5%,最大力总延伸率A_gt 11.5%～14.0%,实测抗拉强度与实测屈服强度之比R_m⁰/R_eL⁰为1.25～1.32,实测屈服强度与GB/T 1499.2-2018标准要求的最低屈服强度之比R_eL⁰/R_eL为1.08～1.16,因此,钢筋的力学性能满足GB/T 1499.2-2018标准要求。生产出的Φ40 mm HRB500E钢筋的微观组织为铁素体+珠光体,晶粒度为9.5～10级。

Productive Practice of Hot-Rolled Φ6 ~ 40 mm HRB500E Reinforcing Steel

According to GB/T 1499. 2-2018 standard, the internal controlled composition of Φ36 - 40 mm HRB500E rebar is designed as (% ) 0.22 ~0.25C,0.60 ~0.70Si, 1.50 ~ 1.60Mn, 0.11 ~0.13V,P≤ 0.045 ,S≤ 0.045 in shuigang. The productive process such as steelmaking in l00t top and bottom combined blown converter- tapping with slag stopping-deoxidization and alloying-LF refining-continuous casting of 160 billet-reheating of billet -rolling of rebar-air cooling is used. The mechanical properties of Φ 36 mm HRB500E rebar are as follows: yield strength R_eL⁰ 540 -580 MPa, tensile strength R_m⁰ 705 ~ 735 MPa, percentage elongation after fracture A 15.5% ?20.5% , total elongation at maximum force A_gt 11.5% ~14.0%,the ratio of actual measured tensile strength to actual measured yield strength R_m⁰/R_eL⁰ is 1.25 ~ 1. 32, the ration of actual measured yield to yield strength stipulated in GB/T 1499. 2-2018 R_eL⁰/R_eL⁰ is 1.08 ?1.16, therefore, mechanical properties of the rebar meet requirements of GB/T 1499.2-2018 standard. The microstructure of Φ40 mm HRB500E rebar produced is ferrite and pearite, its grain size is 9.5 ~ 10 grade.